In damps, hot and coal-dust mines with a high explosion risk or in steep dip stopes, especially in the case of strong coal, the breaking of coal layers at higher levels (i.e. a height of 6 m or more above the entry), can not be realized by the damp-free breaking methods applied up till now.
Also by injection and long hole high pressure air breaking, as a rule, only a section of 5-6 m length above the entry tears away, and consequently, also the immediate top wall above the broken ground tears away after a brief time, the top wall detritus soiling the already broken coal and the incipient caving impedes the further breaking the coal mass above the ripping.
The breaking coal by conventional brizant explosives (i.e. by those with violent effect) can not be used at all for reasons of safety. The breaking by conventional "damp-proof" explosives can be realized on the same grounds only applying blasting charges of small mass, but this method is not satisfactory for the breaking of strong coal in a great mass. The blasting charge containing explosives identified as damp-proof explosives also cannot be applied in a great mass in the case of steep dip coal deposits because the coal wall surrounding the bore hole can tear out and the blasting charge previously set can fire the damp medium in the region.